Marion wrote:

7. My recording guy said that he could supply me with an ISRC number. I notice that many CDs have a code of letters and numbers on the spine - for example, a Seamus Kennedy CD has SK-0012. Is that the ISRC number? What is its function?

The ISRC (International Standard Recording Code) is the international identification system for sound recordings and music videorecordings. Each ISRC is a unique and permanent identifier for a specific recording which can be permanently encoded into a product as its digital fingerprint. Encoded ISRC provide the means to automatically identify recordings for royalty payments.

http://www.ifpi.org/content/section_resources/isrc.html